Vacuum-valve.



0. S. SLEEPBR.

VAGUUM VALVE.

YMPLIUATION FILED 111111.29. 1911.

Patented Nov. 18, 1913.

Z SHEETS-SHEET 1.

TM5-Zvw.; Je 5 11%./

0. S. SLEEPER.

VACUUM VALVE.

APPLIOATION HLED MAR. 29, 1911.

Patented N 0V. 18, 1913.

2 SHEETS-SHEET 2.

UNrrED s'rATEs PATENT oEErcE.

OLIVER S. SLEEPEB, OF BUFFALO, NEW YORK, ASSIGNOR TO BUFFALO FOUNDRY MACHINE COMPANY, 0F BUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

VACUUM-VALVE.

To all whom t may concern:

Be it known that I, OLIVER S. SLEEPER, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented new and useful Improvements in Vacuum-Valves, of which the following is a specification.

This invention relates to vacuum valves which are employed in connection with vacuum drying apparatus for continuously introducing or feeding into the vacuum chamber the material which is to bedried or desiccated and also for continuously discharging from the vacuum chamber the material which has been dried, ywit-hout admitting any of the external air into the vacuum chamber while thus feeding the material into this chamber or removing the same therefrom and thereby avoiding the reduction of the vacuum in this chamber while the machine is in operation.

inasmuch as the vacuum within the drying or vacuum chamber causes the plugs of valves controlling the inlet and outlet thereof to be pressed by the external air against the seats of their casings with a comparatively heavy pressure, these parts of the valves soon become worn unduly if no provision is made to relieve the frictional contact between the valve plugs and casings on that side where these parts are pressed together by the vacuum produced in the drying chamber.

lit is the object of this invention to provide simple, eiiicient and easily adjustable means for controlling the frictional contact hetween the valve casing and plug where the same are pressed together by the vacuum within the drying chamber and also to provide improved means for evacuating any air from the pockets in the plug of the valve in passing from the inlet to the outlet thereof or vice versa.

In the accompanying drawings consisting of 2 sheets: Figure 1 is a side elevation of a vacuum valve embodying one form of my improvements. Fig. 2 is a top plan view thereof. Fig. 3 is a vertical transverse section in line 3-3, Fig. 2. Fig. 4 is a vertical longitudinal section in line 4 4, Fig. 1. Fig. 5 is a fragmentary section taken in line 5 5, Fig. 3. Fig-6 is a fragmentary side elevation showing a modification of my ininvention.

Similar letters of reference indicate corre- Specication of Letters Patent.

Application led March 29, 1911.

Patented N ov. 18,191.3. Serial No. 617,723.

spending parts throughout the several views.

The construction of valve which is shown 1n the drawings can be used either as an inlet or feed valve for supplying the material to be dried to the vacuum or drying chamber or as an outlet or delivery valve for discharging the dried material from the vacuum chamber. In the position of the parts shown in the drawings this valve is adapted for use as an outlet or delivery valve and the same will therefore be first described as such. rl`he casing of this valve comprises a cylindrical body, barrel or shell A which 1s provided on one side and preferably at the top with an upwardly projecting inlet nipple or passage a and at its opposite or lower side with a downwardly projecting outlet nipple or passage al. The inlet nipple is adapted to be connected at its up er end with the outlet of the vacuum chamlier while its lower end opens into the bore of the cylindrical body of the casing. The outlet nipple or passage communicates at its upper end with the bore of the valve body while its lower end is adapted to deliver the dried material into a suitable receptacle.

B represents the cylindrical plug of the valve which rotates within the body of the casing and is fitted comparatively closely at its periphery against the bore of thc body.

At its periphery the rotatable plug of the valve is provided with a plurality of outwardly opening pockets b which are arranged in an. annular row and which are moved successively into register with the inlet and the outlet of the valve casing, whereby each valve as it passes the inlet is filled with a quantity of the material which has been dried and upon reaching the outlet of the casing discharges the material from the pocket.

It has been found in practice that owing to the high vacuum within the vacuum chamber, with which the valve casing is connected, the valve plug is pressed against the casing on that side toward thc vacuum chamber with such force that the friction between the valve plug and casing not only would heat the valve unduly but would also cause the same to wear rapidly if no provision is made to prevent this. For this purpose the plug of the valve is so mounted within the casing and associated with a controlling device whieh permits of relieving and regulating the pressure which it is possible for the plug to exert against the valve casing and still effectively seal the passage betweenv the interior of the vacuum chamber and the external atmosphere and permitting a free discharge of the material therefrom. In its preferred form the means for this purpose which are shown in the drawings are constructed as follows: C, C representl two heads or side pieces which are secured to opposite ends of the cylindrical body of the valve casing and lap inwardly over the adjacent ends of the valve plug so as to confine the plug within the casing and hold the same against axial movement, as shown in Fig. 4. Each of these side pieces is provided with a guideway c extending diametrically across the same and in line with the direction in which the vacuum within the driving chamber causes the external air pressure to move the valve plug toward the valve chamber. At that end of this guideway which is farthest from the vacuum chamber the same is provided with a cross piece D which is preferably made separate from the respective head and mounted at its opposite edges in transverse grooves d formed in the walls of the guideway, as shown in Fig. 1. E, E represent two bearings or bearing boxes which are arranged on opposite sides of the valve plug and each of which is mounted to slide radially in the diametrical guideway of one of the heads of the casing. F represents a shaft upon the central part of which the valve plug is mounted so as to turn therewith and which is journaled on opposite sides of the valve plug in the bearings E, E. This shaft may be turned by any suitable means in the direction of the arrow indicated in Fig. 3 so as to bring each of its pockets successively and alternately into register with the inlet and outlet of the valve casing. The means shown in the drawings for thus turning the valve plug comprise a counter shaft G journaled in stationary bearings g on one side of the valve casing and provided at one end with the gear pinion 71, which meshes with the gear pinion H on the valve shaft while its opposite end is provided with a pulley I adapted to receive a driving belt.

The movement of the valve plug under the action of the vacuum within the vacuum chamber, or in other words due to the pressure of the external atmosphere, is counteracted or ofi set by a controlling device which is yielding and adjustable in accordance with the requirements. In its preferred form this controlling device comprises two spiral springs J each of which is arranged wit-hin one of the guideways at that end thereof nearest to the vacuum chamber and bearing at its outer end against the adjacent bearing box E of the valve shaft, a follower y' guided in a radial socket c formed in the respective head at the inner end of the respective guideway and engaging with the inner end of the spring J, and an adjusting screw Zarranged in a threaded opening on the respective head and engaging with the inner end of the follower j, as shown in Fig. 4. Asthe valve plug is pressed laterally inward toward the vacuum chamber by the pressure of the external atmosphere while the machine is in operation, this movement of the valve plug is resisted by the tensionof the springs J, thereby relieving the friction between the inner coperating parts of the periphery of the valve plug and the bore of the valve casing. By turning the adjusting screws the tension of the springs may be regulated so as to permit the valve plug to engage at its inner side with the bore of the valve casing only with such a degree of pressure as will insure a suiciently tight fit between the parts to avoid leakage of air and reduce the friction to a minimum, thereby avoiding undue heating and wear 4on the valve.

In order to cool the valve and oisetsuch heat as is produced by the necessary frictional contact between the plug and casing the inner part of the valve casing next to the vacuum or drying chamber is provided with a jacket m through which water or other cooling medium may be circulated for the purpose of preventing excessive heating of this part of the valve.

When the machine is operated without a vacuum in the vacuum chamber the springs J, in the absence of any provision to prevent it, would move the valve plug away from the inner side of the bore of the casing an undue extent. This, however, is prevented b means of two adjustable stops n which pre erably consist of screws each of which is arranged in one of the cross pieces D` and bears against the outer side of one of the bearings of the valve shaft, whereby these screws serve as adjustable stops which hold the working face of the rotary plug close to the working face of the valve casing and prevent these parts from separating unduly when the vacuum in the machine is de stroyed, thereby avoiding undue leakage upon starting the drying machine.

As each of the pockets of the valve after discharging its load through the outlet of the casing is filled with air the latter if earried to the inlet of the valve casing would add moisture to the contents of the drying chamber and thus impair the eiiicie'ncy of the machine accordingly inasmuch as the exhausting device would be called upon to exhaust or evacuate each one of the pockets as it registers with the inlet of the valve casof vacuum in the drying chamber and also dry the additional air supplied by the pockcts.

In order to avoid carrying any of the external atmosphere by means of the pockets of the valve plug into the drying chamber and thereby preventing the entrance of any external moisture into the machine cach of the pockets of the valve plug is evacuated as it passes from the outlet of the valve cas* ing to the inlet thereof. The preferred means for this purpose shown in Figs. 3 and 5 of the drawings consist ot' an evacuating pocket o formed in the body of the valve casing between the inlet and outlet thereof and provided with a comparatively wide inner end which opens into the bore of the valve casing anda comparatively narrow outer end which is connected by a pipe y) or otherwise with au air exhausting device whereby the evacuating pocket o and any spaces comn'iunicating therewith are constantly ex hausted of the air contained in the same. s each pocket of the valve plug passes from the outlet to the inlet of the casing and comes into register with the evacuating pocket the air in this valve pocket is exhausted therefrom through the evataiating pocket by the exhausting device connected therewith. By making the inner end of this evacuating pocket comparatively wide in a direction lengthwise of the axis of the valve plug and casing this e Yacuating pocket communicates over a considerable area with the valve plug pockets and thereby enables the same to be evacuated quickly and effectively and by making the outer end ofthe evacuating pocket comparatively narrow it permits of conveniently connecting the same with the piping leading to the exhausting device. lVhen this valve is used at the inlet of the vacuum drying chamber the application ot' the same to the vacuum drier reversed and tbe movenient ofthe plug is also revr` sed, in other werds, the inlet and outlet of the valve shown in Fig. 9 become the outlet and inlet, respectively, when the valve is used at the inlet of the vacuum chamber, and the plug is turned in a direction opposite to that shown by the arrow in Fig. 3, so that the pockets of the valve plug are evacuated after discharging their load into the drying machine and before being filled with another load from the supply hopper, thereby ena bling these pockets to be filled without inter ferei'ice from any air which otherwise might be present in the, valve pockets.

Instead `of yieldingly resisting the movcment of the valve plug toward the vacuun'i chamber Ibv the means shown in Figs. l., il and 4l, the movement. of the valve plug in this direction may be positively limited by a non-elastic adjusting device such as that shown in Fig. (i. In this construction each of the bearings E of the valve plug shaft F engages not only on its rear side with an adjusting screw n but also on its inner side with an adjusting screw jl which works in a cross piece J1 fitted at its ends in transverse grooves j2 in the walls of the guldeway c. rlhe screws jl of both bearings E are so adjusted that the latter upon engaging these screws will hold the valve plug so that it just touches the bore of the casing on the side toward the vacuum chamber but does not bear firmly against the same, whereby the pressure of the external atmosphere on the valve plug is sustained by the bearings .E which are of comparatively small area and do not heat or wear unduly, while the periphery of the valve plug and the bore of the casing which have a relatively large arca of contact are saved from undue friction, heat and wear.

l claim as my invention:

l. A vacuum valve comprising a cylindrical valve chamber having an inlet and an outlet one of which is adapted to be connected with a vacuum chamber, a rotatable valve plug arranged in said chamber and provided at its periphery with an annular row of outwardly opening pockets which are brought successively into register with said inlet and outlet, and a controlling device associated with said valve plug and operating to relieve the pressure of the valve plug against that side of the valve chamber against which the valve plug is drawn by the action of said exhaust device.

2. A vacuum valve comprising a cylindrical valve chamber having au inlet and an outlet one of which is adapted to be connected with a vacuum chamber, a rotatable valve plug arranged in said chamber and provided at its periphery with an annular row of outwardly opening pockets which are brought successively into register with said inlet and outlet` and a controlling device as sociated with said valve plug and operating to relieve the pressure of the valve plug against that side of the valve chamber against which the valve plug is drawn by the action of said exhaust device, said controlling device comprising springs arranged to resist the movement ol the valve plug toward said vacuum chamber.

2i. vacuum valve comprising a cylindrical valve chamber having an inlet and an outlet one of which is adapted to be connected with a vacuum chamber, a rotatable valve plug arranged in said chamber and provided at its periphery with an annular row of outwardly opening pockets which are brought successively into register with said inlet and outlet, and a controlling device associated with said valve plug and operating to relieve the pressure of the valve plug against that side of the valve chamber against which the valve plug is drawn by the action of said exhaust device, said controlling device comprising springs arranged to resist the movement of the valve plug toward said vacuum chamber and adjusting screws for regulating the tension of sai springs.

4. A vacuum valve comprising a cylindricalvalve chamber having an inlet and an outlet one of which is adapted to be connected with a vacuum chamber, a rotatable valve plug arranged in said chamber and provided at its periphery with an annular row of outwardly opemng pockets which are brought successively into register with said inlet and outlet, and a controlling device associated With said valve plug and operating to relieve the pressure of the valve plug against that side of the valve chamber against which the valve plug is drawn by the action of said exhaust device, said controlling device comprising springs arranged to resist the movement of valve plug toward said vacuum chamber, adjusting screws for regulating the tension of said springs and adjustable stops which limit the movement of said valve plug under the action of said springs.

5. A vacuum valve comprising a cylindrical valve chamber having an inlet and an outlet one of which is adapted to be connected with a vacuum chamber, a rotatable valve plug arranged in said chamber and provided at its periphery with an annular rowof outwardly openlng pockets which are brought successively into register with said inlet and outlet, a shaft on which said valve plug is mounted, bearings which are arranged on opposite sides of the valve and in which opposite ends of said shaft are journaled, guideways in which said bearings slide, springs operating to resist the movement of said bearings and associated parts toward said vacuum chamber, and adjusting screws for regulating the tension of said springs.

6. A vacuum valve comprising a cylindrical valve chamber having an inlet and an outlet one of which is adapted to be connected with a vacuum chamber, a rotatable valve .plug arranged in said chamber and provided at its periphery with an annular row of outwardly opemng pockets which are brought successively into register with said inlet and outlet, a shaft on which said valve plug is mounted, bearings which are arranged on opposite sides of the valve and in which opposite ends of said shaft are journaled, guid'eways in which lsaid bearings slide, springs operating to resist the movement of said bearings and associated parts toward said vacuum chamber, adjusting screws for regulating the tension of said springs, and stop screws arranged to be engaged by bearings and limit the movement of the same under the actionof said springs.

7. A vacuum valve comprising a cylindrical valve chamber having an inlet and an outlet and an evacuating pocket between its inlet and outlet which has a wide inner end opening into the bore of said valve chamber and a narrow outlet which is adapted tovbe connected with an air exhausting device, and a rotary valve plug arranged in said valve chamber and having a plurality of outwardly opening pockets at its periphery.

Witness my hand this 27thday of March,

OLIVER S. SLEEPER.

Witnesses:

THEO. L. Por?, ANNA Herero. 

